1. Technical Field
The present invention relates generally to the field of computer systems and more specifically to a method, system, and computer program product for providing highly available, redundant optical modules using a single network connection.
2. Description of Related Art
Optical connections in a network are made between optical modules, also called optical transceivers, such as the Gigabaud Link Module (GLM) and GigaBaud Interface Converter GBIC, and fiber optic cables. Optical modules such as the GLM and GBIC are designed such that they can be replaced during normal operation in part due to their relatively high failure rate. The potential for an optical module failure per unit time in large scale high speed network environments can be very high.
A first order evaluation depicts the problem that this behavior presents. A typical large scale optical storage network consists of a cascade of eight 256 port switches with assorted attached clients, hosts, storage servers, protocol converters, and routers. The total number of optical components or modules contained in this network is on the order of 8×256×2=4096. A reasonable expectation time to failure in this environment is approximately 7.7 days or approximately one optical module failure per week. Optical failures per unit time increase in direct proportion to the number of ports being considered. Large scale optical networks, and especially storage networks, cannot tolerate such high failure rates from both an operational and maintenance perspective.
In many cases optical module failures represent a single point of failure in networks and can affect the normal operation of the network and business continuity. When an optical module fails it must be replaced as soon as possible in order to bring network operations back to the normal or expected state. Since optical module failures are in most cases unpredictable and occur at high rates, they generally have a large impact for on-line operations and affect the ability to maintain the network in an orderly and scheduled manner.
Prior art network adapter cards included only the single optical module. A prior art approach to solve the problem has been to add extra network adapter cards where each card had only the single optical module. This approach requires additional adapter slots to accommodate the additional network interface cards. Additional cabling is also necessary. This approach also doubles the overall failure rate.
Prior art embedded network interfaces are integrated directly on the network component circuit board, storage component circuit board, or computer circuit board. A prior art approach to solve the problem has been to add an extra network interface where each interface contains a single optical module. This approach requires twice as much circuitry, circuit board space, and cabling. This approach also doubles the overall failure rate.
Therefore, a need exists for a method, system, and computer program product for providing highly available, redundant optical modules using a single network connection.